usbcore: resume device resume recursion
This patch (as717b) removes the existing recursion in hub resume code:
Resuming a hub will no longer automatically resume the devices attached
to the hub.
At the same time, it adds one level of recursion: Suspending a USB
device will automatically suspend all the device's interfaces. Failure
at an intermediate stage will cause all the already-suspended interfaces
to be resumed. Attempts to suspend or resume an interface by itself will
do nothing, although they won't return an error. Thus the regular
system-suspend and system-resume procedures should continue to work as
before; only runtime PM will be affected.
The patch also removes the code that tests state of the interfaces
before suspending a device. It's no longer needed, since everything
gets suspended together.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index a372332..a391120 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1662,9 +1662,6 @@
"gone after usb resume? status %d\n",
status);
else if (udev->actconfig) {
- unsigned i;
- int (*resume)(struct device *);
-
le16_to_cpus(&devstatus);
if ((devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP))
&& udev->parent) {
@@ -1675,24 +1672,9 @@
USB_DEVICE_REMOTE_WAKEUP, 0,
NULL, 0,
USB_CTRL_SET_TIMEOUT);
- if (status) {
+ if (status)
dev_dbg(&udev->dev, "disable remote "
"wakeup, status %d\n", status);
- status = 0;
- }
- }
-
- /* resume interface drivers; if this is a hub, it
- * may have a child resume event to deal with soon
- */
- resume = udev->dev.bus->resume;
- for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
- struct device *dev =
- &udev->actconfig->interface[i]->dev;
-
- down(&dev->sem);
- (void) resume(dev);
- up(&dev->sem);
}
status = 0;
@@ -1802,15 +1784,7 @@
} else
status = finish_port_resume(udev);
if (status < 0)
- dev_dbg(&udev->dev, "can't resume, status %d\n",
- status);
-
- /* rebind drivers that had no suspend() */
- if (status == 0) {
- usb_unlock_device(udev);
- bus_rescan_devices(&usb_bus_type);
- usb_lock_device(udev);
- }
+ dev_dbg(&udev->dev, "can't resume, status %d\n", status);
return status;
}
@@ -1830,6 +1804,9 @@
msleep(10);
status = finish_port_resume(udev);
}
+
+ if (status == 0)
+ usb_resume_both(udev);
usb_unlock_device(udev);
#endif
return status;
@@ -1901,51 +1878,8 @@
}
}
+ /* tell khubd to look for changes on this hub */
hub_activate(hub);
-
- /* REVISIT: this recursion probably shouldn't exist. Remove
- * this code sometime, after retesting with different root and
- * external hubs.
- */
-#ifdef CONFIG_USB_SUSPEND
- {
- unsigned port1;
-
- for (port1 = 1; port1 <= hdev->maxchild; port1++) {
- struct usb_device *udev;
- u16 portstat, portchange;
-
- udev = hdev->children [port1-1];
- status = hub_port_status(hub, port1, &portstat, &portchange);
- if (status == 0) {
- if (portchange & USB_PORT_STAT_C_SUSPEND) {
- clear_port_feature(hdev, port1,
- USB_PORT_FEAT_C_SUSPEND);
- portchange &= ~USB_PORT_STAT_C_SUSPEND;
- }
-
- /* let khubd handle disconnects etc */
- if (portchange)
- continue;
- }
-
- if (!udev || status < 0)
- continue;
- usb_lock_device(udev);
- if (portstat & USB_PORT_STAT_SUSPEND)
- status = hub_port_resume(hub, port1, udev);
- else {
- status = finish_port_resume(udev);
- if (status < 0) {
- dev_dbg(&intf->dev, "resume port %d --> %d\n",
- port1, status);
- hub_port_logical_disconnect(hub, port1);
- }
- }
- usb_unlock_device(udev);
- }
- }
-#endif
return 0;
}
@@ -2602,17 +2536,6 @@
usb_get_intf(intf);
spin_unlock_irq(&hub_event_lock);
- /* Is this is a root hub wanting to reactivate the downstream
- * ports? If so, be sure the interface resumes even if its
- * stub "device" node was never suspended.
- */
- if (i) {
- dpm_runtime_resume(&hdev->dev);
- dpm_runtime_resume(&intf->dev);
- usb_put_intf(intf);
- continue;
- }
-
/* Lock the device, then check to see if we were
* disconnected while waiting for the lock to succeed. */
if (locktree(hdev) < 0) {
@@ -2629,6 +2552,13 @@
goto loop;
}
+ /* Is this is a root hub wanting to reactivate the downstream
+ * ports? If so, be sure the interface resumes even if its
+ * stub "device" node was never suspended.
+ */
+ if (i)
+ usb_resume_both(hdev);
+
/* If this is an inactive or suspended hub, do nothing */
if (hub->quiescing)
goto loop;